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1.
Br J Dermatol ; 179(3): 747-749, 2018 09.
Article in English | MEDLINE | ID: mdl-29603722

ABSTRACT

We present the case of a 77-year-old male patient with more than 50 basal cell carcinomas on the head and upper trunk. The patient did not respond to several lines of treatment, including surgery, imiquimod, retinoids, itraconazole and therapy with the hedgehog inhibitor vismodegib. The patient responded well to off-label therapy with the anti-programmed death-1 antibody pembrolizumab after four infusions.


Subject(s)
Antibodies, Monoclonal, Humanized/administration & dosage , Basal Cell Nevus Syndrome/drug therapy , Programmed Cell Death 1 Receptor/antagonists & inhibitors , Repressor Proteins/genetics , Skin Neoplasms/drug therapy , Aged , Basal Cell Nevus Syndrome/genetics , Basal Cell Nevus Syndrome/immunology , Humans , Infusions, Intravenous , Male , Mutation , Off-Label Use , Skin Neoplasms/genetics , Skin Neoplasms/immunology , Treatment Outcome
4.
J Fish Biol ; 88(5): 1811-34, 2016 May.
Article in English | MEDLINE | ID: mdl-27021219

ABSTRACT

Here, multi-locus sequence data are coupled with observations of live colouration to recognize a new species, Eviota punyit from the Coral Triangle, Indian Ocean and Red Sea. Relaxed molecular clock divergence time estimation indicates a Pliocene origin for the new species, and the current distribution of the new species and its sister species Eviota sebreei supports a scenario of vicariance across the Indo-Pacific Barrier, followed by subsequent range expansion and overlap in the Coral Triangle. These results are consistent with the 'centre of overlap' hypothesis, which states that the increased diversity in the Coral Triangle is due in part to the overlapping ranges of Indian Ocean and Pacific Ocean faunas. These findings are discussed in the context of other geminate pairs of coral reef fishes separated by the Indo-Pacific Barrier.


Subject(s)
Coral Reefs , Fishes/classification , Genetic Speciation , Animal Distribution , Animals , Biodiversity , Fishes/genetics , Fishes/physiology , Geography , Indian Ocean , Pacific Ocean , Sequence Analysis, DNA , Species Specificity
5.
Anaesthesist ; 65(3): 203-11, 2016 Mar.
Article in German | MEDLINE | ID: mdl-26886384

ABSTRACT

BACKGROUND: Medical emergency situations and even cardiac arrest can occur during treatment of patients in therapeutic hyperbaric chambers just as in other clinical departments; therefore, high quality structured management should be implemented for dealing with emergencies in this special working area. To ensure this the emergency medical treatment should not only be performed according to the current state of medical knowledge but needs to take the special features of the hyperbaric environment including safety aspects into account. METHOD: This article presents a description of the implementation and effects of routine emergency and resuscitation training at a center for hyperbaric medicine. RESULTS: By simulation of emergencies in a hyperbaric chamber it rapidly became clear that the treatment of medical emergencies and cardiac arrest under hyperbaric conditions has some special features and due to safety aspects cannot always be performed according to current medical guidelines. At the time of this simulation in a real life working environment, previously unknown structural and logistic problems became obvious whereby the solutions contributed to a significant improvement of structural and process quality and could potentially also improve the outcome quality. Furthermore, a positive and lasting learning effect in the fields of quality of resuscitation measures, organization of the workplace, communication skills, logistics and safety aspects was detectable by analyzing participant performance over a period of 4 years. On the part of the participating staff a positive feedback and high acceptance of emergency simulator training was confirmed. CONCLUSION: Through annual compulsory emergency training of the complete staff of the hyperbaric unit at the actual workplace, a structural and confident approach to dealing with emergencies and resuscitation situations was observed. By the use of on-site simulator training even in specialized hospital units, deficits and tentativeness regarding logistics, course of action, organization and communication in emergency situations can be minimized to provide optimum patient care in a real life emergency situation by focusing on the medical measures.


Subject(s)
Cardiopulmonary Resuscitation/education , Hyperbaric Oxygenation , Aged , Aged, 80 and over , Carbon Monoxide Poisoning/therapy , Clinical Competence , Communication , Emergency Medical Services , Female , Fractures, Bone/therapy , Heart Arrest/therapy , Humans , Male , Manikins , Patient Care Team , Patient Safety , Shock/therapy , Suicide, Attempted , Young Adult
6.
Vox Sang ; 108(1): 89-95, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25334002

ABSTRACT

BACKGROUND AND OBJECTIVES: Buffy coat (BC) volume reduction was evaluated in leucapheresis (LA) harvests due to the target monocyte yield and the red blood cell (RBC) content. A packed erythrocyte volume (PEV) of 7.5 ml should not be exceeded to avoid RBC debulking with loss of leucocytes (WBCs) and the monocyte fraction during monocyte counterflow elutriation, a next step of monocyte enrichment prior to cell culture. MATERIALS AND METHODS: Two hundred and fifty-three 5-l leucaphereses (autoMNC program) performed in 102 healthy blood donors (24 female and 78 male donors) were retrospectively analysed. Different categories of BC volumes were compared due to the quality of the LA products measured by blood counts and flow cytometry. RESULTS: Collection of maximum BC volume of 10 ml and more each collection cycle (product volume: 169 ± 21 ml) resulted in 1.58 ± 0·41 × 10e9 CD14(+) monocytes and high volume of packed erythrocyte (18.4 ± 8.8 ml). Low BC volume collection below 6 ml each collection cycle produced only 1.07 ± 0.40 × 10e9 CD14(+) monocytes but reduced PEV significantly by 64% (6.7 ± 4.1 ml). CONCLUSION: By reduction of the BC volume, the PEV in LA products could be reduced, which is a precondition for counterflow elutriation of monocytes. A BC volume between 7 and 8 ml per collection cycle should be adjusted to reduce PEV to 7.5 ml without relevant monocyte loss.


Subject(s)
Blood Buffy Coat/cytology , Leukapheresis/methods , Leukapheresis/standards , Blood Buffy Coat/immunology , Female , Hematocrit , Humans , Male
7.
Nature ; 451(7175): 176-80, 2008 Jan 10.
Article in English | MEDLINE | ID: mdl-18075503

ABSTRACT

Biodegradation of crude oil in subsurface petroleum reservoirs has adversely affected the majority of the world's oil, making recovery and refining of that oil more costly. The prevalent occurrence of biodegradation in shallow subsurface petroleum reservoirs has been attributed to aerobic bacterial hydrocarbon degradation stimulated by surface recharge of oxygen-bearing meteoric waters. This hypothesis is empirically supported by the likelihood of encountering biodegraded oils at higher levels of degradation in reservoirs near the surface. More recent findings, however, suggest that anaerobic degradation processes dominate subsurface sedimentary environments, despite slow reaction kinetics and uncertainty as to the actual degradation pathways occurring in oil reservoirs. Here we use laboratory experiments in microcosms monitoring the hydrocarbon composition of degraded oils and generated gases, together with the carbon isotopic compositions of gas and oil samples taken at wellheads and a Rayleigh isotope fractionation box model, to elucidate the probable mechanisms of hydrocarbon degradation in reservoirs. We find that crude-oil hydrocarbon degradation under methanogenic conditions in the laboratory mimics the characteristic sequential removal of compound classes seen in reservoir-degraded petroleum. The initial preferential removal of n-alkanes generates close to stoichiometric amounts of methane, principally by hydrogenotrophic methanogenesis. Our data imply a common methanogenic biodegradation mechanism in subsurface degraded oil reservoirs, resulting in consistent patterns of hydrocarbon alteration, and the common association of dry gas with severely degraded oils observed worldwide. Energy recovery from oilfields in the form of methane, based on accelerating natural methanogenic biodegradation, may offer a route to economic production of difficult-to-recover energy from oilfields.


Subject(s)
Methane/biosynthesis , Petroleum/metabolism , Alkanes/chemistry , Alkanes/metabolism , Anaerobiosis , Archaea/genetics , Archaea/metabolism , Bacteria/genetics , Bacteria/metabolism , Biodegradation, Environmental , Canada , Carbon Dioxide/chemistry , Carbon Dioxide/metabolism , Carbon Isotopes/analysis , Gases/analysis , Gases/chemistry , Gases/metabolism , Methane/chemistry
9.
Ultrasound Obstet Gynecol ; 40(2): 215-8, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22223551

ABSTRACT

OBJECTIVE: Stress urinary incontinence (SUI) is a common health problem in women. Reflex activation of muscular pelvic floor structures may play a role in preserving continence. In this study we aimed to analyze reflex pelvic floor activity on coughing in women seen for urodynamic testing. METHODS: In a retrospective cohort study we analyzed the data sets of 191 women who attended a tertiary referral service for multichannel urodynamic testing and four-dimensional pelvic floor ultrasound scan between May 2009 and February 2010. Coughs were registered on volume ultrasound at a minimum of 16 Hz and analyzed by postprocessing at a later date, the operator being blinded against all clinical data. RESULTS: Of 175 analyzable cough volume datasets, a levator reflex was seen in 138 (79%), and clitoral reflex movement in 160 (91%). On multivariable analysis there was a significant relationship between urodynamic stress incontinence (USI) and the absence of a levator reflex (P = 0.045), and a negative relationship with the magnitude of such a reflex (P = 0.046). Reflex timing was not associated with SUI or USI. CONCLUSION: Reflex contraction of the levator ani can be observed on translabial ultrasound during sudden increases in intra-abdominal pressure. These reflex contractions are common, even in women with symptoms and signs of pelvic floor dysfunction. The observation of a levator reflex on coughing, and its magnitude, show a weak inverse association with the presence of USI.


Subject(s)
Cough/physiopathology , Muscle Contraction/physiology , Pelvic Floor Disorders/physiopathology , Pelvic Floor/physiopathology , Urinary Incontinence, Stress/physiopathology , Adult , Aged , Aged, 80 and over , Cohort Studies , Female , Humans , Middle Aged , Pelvic Floor/diagnostic imaging , Pelvic Floor Disorders/diagnostic imaging , Reflex , Retrospective Studies , Ultrasonography , Urinary Incontinence, Stress/diagnostic imaging , Urodynamics , Young Adult
10.
Microsurgery ; 30(1): 19-23, 2010.
Article in English | MEDLINE | ID: mdl-19790176

ABSTRACT

Free fibular bone grafting is an effective treatment for early osteonecrosis of the femoral head in young patients. However, recipient vessels are often small rendering microvascular anastomosis difficult. We have developed a novel technique using retrograde flow through the branches of the lateral circumflex femoral artery to use the proximal end of the artery as the recipient vessel. A vessel diameter of up to 5 mm is obtained providing a good match with the peroneal vessels. We used this technique to perform vascularized bone grafting of the femoral head in 10 patients with Ficat grade 2 and 3 osteonecrosis. Pulsatile retrograde flow from the lateral circumflex femoral artery was observed in each case. Retrospective review gave a median follow up of 52 months (range 17-99). Symptoms improved in all 10 cases. There was no radiological deterioration over the period of follow-up in eight cases. One patient underwent conversion to a total hip replacement 24 months after surgery. These results compare favorably with other studies. The lateral circumflex femoral artery turnover technique is a reliable and useful technique in vascularized bone grafting of the femoral head.


Subject(s)
Bone Transplantation/methods , Femoral Artery/surgery , Femoral Vein/surgery , Femur Head Necrosis/surgery , Fibula/blood supply , Microsurgery , Adolescent , Adult , Anastomosis, Surgical , Cohort Studies , Female , Femur Head Necrosis/etiology , Femur Head Necrosis/pathology , Fibula/transplantation , Humans , Male , Regional Blood Flow , Retrospective Studies , Treatment Outcome , Young Adult
11.
Science ; 292(5524): 2037-41, 2001 Jun 15.
Article in English | MEDLINE | ID: mdl-11358995

ABSTRACT

Self-amplified spontaneous emission in a free-electron laser has been proposed for the generation of very high brightness coherent x-rays. This process involves passing a high-energy, high-charge, short-pulse, low-energy-spread, and low-emittance electron beam through the periodic magnetic field of a long series of high-quality undulator magnets. The radiation produced grows exponentially in intensity until it reaches a saturation point. We report on the demonstration of self-amplified spontaneous emission gain, exponential growth, and saturation at visible (530 nanometers) and ultraviolet (385 nanometers) wavelengths. Good agreement between theory and simulation indicates that scaling to much shorter wavelengths may be possible. These results confirm the physics behind the self-amplified spontaneous emission process and forward the development of an operational x-ray free-electron laser.

12.
Anaesthesist ; 58(6): 589-93, 2009 Jun.
Article in German | MEDLINE | ID: mdl-19562396

ABSTRACT

After rescue and transport a patient with severe carbon monoxide poisoning (CO-Hb concentration 82%) was treated by hyperbaric oxygen (HBO) therapy in a pressure chamber. During decompression the patient suffered cardiac arrest due to massive acidosis, hyperpotassaemia, haemoconcentration and elevated CO-Hb level. After successful resuscitation and cardiopulmonary diagnostics, HBO therapy was continued for prophylactic treatment of delayed neurological sequelae. Three months after completing treatment and discharge from hospital there were no neurological sequelae.


Subject(s)
Carbon Monoxide Poisoning/therapy , Hyperbaric Oxygenation , Acidosis/etiology , Air Pressure , Blood Gas Analysis , Carbon Monoxide Poisoning/complications , Carbon Monoxide Poisoning/diagnostic imaging , Carboxyhemoglobin/metabolism , Heart Arrest/etiology , Humans , Hyperkalemia/etiology , Tomography, X-Ray Computed , Vehicle Emissions
13.
G Ital Dermatol Venereol ; 143(4): 235-50, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18833080

ABSTRACT

Dendritic cells as immunotherapeutic agents against malignancies have been applied for over ten years. Proof of principle studies demonstrated immunogenicity of dendritic cells even in patients suffering from advanced malignancies. Clinicians and immunologists early focused on this innovative immunotherapeutic approach in metastasized malignant melanoma--a malignancy so far resisting most traditional oncologic treatment modalities. In this review we summarize the experience obtained of dendritic cell therapy in patients with malignant melanoma and state past, present and future obstacles. So far over 850 melanoma patients in 51 trials have been reported since 1998. Within these trials there exists a vast heterogeneity concerning type of dendritic cell applied, differentiation and maturation of dendritic cells, type of antigen target and nature, application mode, number of cells applied, vaccination intervals in addition to patients treated at various stages of melanoma. A minority of patients developed anticipated autoimmune adverse events in addition to expected immune system activation symptoms such as fever and local site reaction. As only solitary World Health Organization (WHO) grade III or IV adverse events were reported one can state that dendritic cell therapy is safe. Objective clinical responses have repeatedly been observed in a minority of heavily pretreated and far advanced melanoma patients. Future challenges include optimization and standardization of dendritic cell generation and application, addition of synergistic immunomodulatory agents to enhance immunogenicity and block tumor escape and treatment of patients at earlier stages of disease who will benefit from this innovative therapy.


Subject(s)
Cancer Vaccines/administration & dosage , Dendritic Cells/immunology , Immunotherapy/methods , Melanoma/therapy , Skin Neoplasms/therapy , Cancer Vaccines/adverse effects , Humans , Immunotherapy/adverse effects , Melanoma/secondary , Skin Neoplasms/secondary
14.
J Cancer Res Clin Oncol ; 143(10): 1977-1984, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28616701

ABSTRACT

INTRODUCTION: PD-L1 is established as a predictive marker for therapy of non-small cell lung cancer with pembrolizumab. Furthermore, PD-L1 positive melanoma has shown more favorable outcomes when treated with anti-PD1 antibodies and dacarbazine compared to PD-L1 negative melanoma. However, the role of PD-L1 expression with regard to response to checkpoint inhibition with anti-CTLA-4 is not clear, yet. In addition, the lack of standardization in the immunohistochemical assessment of PD-L1 makes the comparison of results difficult. In this study, we investigated the PD-L1 gene expression with a new fully automated technique via RT-PCR and correlated the findings with the response to the anti-CTLA-4 antibody ipilimumab. MATERIALS AND METHODS: Within a retrospective multi-center trial, PD-L1 gene expression was evaluated in 78 melanoma patients in a total of 111 pre-treatment tumor samples from 6 skin cancer centers and analyzed with regard to response to ipilimumab. For meaningful statistical analysis, the cohort was enriched for responders with 30 responders and 48 non-responders. Gene expression was assessed by quantitative RT-PCR after extracting mRNA from formalin-fixed paraffin embedded tumor tissue and correlated with results from immunohistochemical (IHC) stainings. RESULTS AND DISCUSSION: The evaluation of PD-L1 expression based on mRNA level is feasible. Correlation between PD-L1 expression as assessed by IHC and RT-PCR showed varying levels of concordance depending on the antibody employed. RT-PCR should be further investigated to measure PD-L1 expression, since it is a semi-quantitative method with observer-independent evaluation. With this approach, there was no statistical significant difference in the PD-L1 expression between responders and non-responders to the therapy with ipilimumab. The evaluation of PD-L1 expression based on mRNA level is feasible. Correlation between PD-L1 expression as assessed by IHC and RT-PCR showed varying levels of concordance depending on the antibody employed. RT-PCR should be further investigated to measure PD-L1 expression, since it is a semi-quantitative method with observer-independent evaluation. With this approach, there was no statistical significant difference in the PD-L1 expression between responders and non-responders to the therapy with ipilimumab.


Subject(s)
B7-H1 Antigen/biosynthesis , Ipilimumab/administration & dosage , Melanoma/drug therapy , Melanoma/immunology , RNA, Messenger/metabolism , Skin Neoplasms/drug therapy , Skin Neoplasms/immunology , Adult , Aged , Aged, 80 and over , B7-H1 Antigen/genetics , B7-H1 Antigen/immunology , Case-Control Studies , Female , Gene Expression , Humans , Immunohistochemistry , Male , Melanoma/genetics , Melanoma/pathology , Middle Aged , Neoplasm Staging , Predictive Value of Tests , RNA, Messenger/genetics , Real-Time Polymerase Chain Reaction , Retrospective Studies , Skin Neoplasms/genetics , Skin Neoplasms/pathology
15.
Endocrinology ; 128(2): 1015-20, 1991 Feb.
Article in English | MEDLINE | ID: mdl-1899215

ABSTRACT

Experiments were designed to determine whether vasoactive intestinal polypeptide (VIP), reported to stimulate basal PRL secretion, affects PRL processing by lactotrophs. Initially, rat anterior pituitary quarters were incubated for 2 h with [3H]leucine, with and without 10(-5) M VIP, and immunoreactive and immunoprecipitable rPRL were measured during 56 mM KCl perifusion to determine total and 3H-labeled PRL, respectively. Inclusion of VIP increased immunoreactive PRL (P less than 0.05), decreased immunoprecipitable PRL (P less than 0.01), and, therefore, decreased the specific activity of labeled PRL (P less than 0.001). These results suggested an enhanced release of newly synthesized PRL before KCl depolarization, thus decreasing the release of labeled PRL. To discriminate between the two PRL pools, newly synthesized and storage, pituitary quarters were incubated with and without 10(-5) M VIP for 4 h with [14C]leucine, 2 h in cold medium and 2 h with [3H]leucine. Immunoprecipitable PRL was measured during perifusion with 56 mM KCl. Data were depicted as the 3H/14C disintegrations per min ratio of PRL released/3H/14C disintegrations per min of total tissue to account for any differences in tissue labeling. This ratio was greater for tissue labeled in the presence of VIP (P less than 0.002). To determine whether VIP, as a secretagogue, differentiates between the newly synthesized and storage pools, VIP was added after pulse chase, as previously described. No preferential release was observed between the two groups. Finally, using the same [3H]- and [14C]leucine-labeling protocol with and without 10(-5) M VIP, tissue was perifused with medium 199 for 1 h, with 10(-5) M TRH for 30 min, with medium 199 for 30 min, and with 56 mM KCl for 1 h. Inclusion of VIP increased the 3H/14C released/3H/14C total tissue ratio during basal perifusion (P less than 0.04) and TRH exposure (P less than 0.05). Within the control group, the TRH ratio was greater than basal (P less than 0.003). These experiments suggest that newly synthesized PRL is preferentially secreted over stored PRL from tissue incubated with VIP during pulse-chase labeling; however, addition of VIP as a secretagogue did not affect either PRL pool preferentially.


Subject(s)
Prolactin/biosynthesis , Thyrotropin-Releasing Hormone/pharmacology , Vasoactive Intestinal Peptide/pharmacology , Animals , Carbon Radioisotopes , In Vitro Techniques , Male , Potassium Chloride/pharmacology , Rats , Rats, Inbred Strains , Time Factors , Tritium
16.
J Clin Pharmacol ; 35(3): 302-5, 1995 Mar.
Article in English | MEDLINE | ID: mdl-7608322

ABSTRACT

The pharmacokinetics of triamcinolone acetonide were studied after intravenous (2 mg), oral (5 mg), and inhaled (2 mg) administration. Triamcinolone acetonide concentrations were measured in plasma by high-performance liquid chromatography/radioimmunoassay. After intravenous administration, triamcinolone acetonide was eliminated with a total body clearance of 37 L/h and a half-life of 2.0 hours. The volume of distribution was 103 L, and oral bioavailability averaged 23%. Absorption was rapid, achieving maximum triamcinolone acetonide levels of 10.5 ng/mL after 1 hour. After inhalation, bioavailability averaged 22% with maximum levels of 2.0 ng/mL observed after 2.1 hours. The resulting systemic levels for all three treatments caused a significant decrease in the number of lymphocytes in blood.


Subject(s)
Triamcinolone Acetonide/pharmacokinetics , Administration, Inhalation , Administration, Oral , Biological Availability , Cross-Over Studies , Half-Life , Humans , Injections, Intravenous , Lymphocyte Count/drug effects , Lymphocytes/drug effects , Male , Metabolic Clearance Rate , Triamcinolone Acetonide/administration & dosage , Triamcinolone Acetonide/pharmacology
17.
J Clin Pharmacol ; 35(12): 1187-93, 1995 Dec.
Article in English | MEDLINE | ID: mdl-8750370

ABSTRACT

Triamcinolone acetonide (TCA) is a corticosteroid that is frequently used in the treatment of asthma. After inhalation, TCA can become systemically available when the inhaled formulation is swallowed, causing undesirable systemic effects. A clinical study was conducted to determine the systemic side effects of TCA after intravenous (2 mg as phosphate ester), oral (5 mg), and inhaled (2 mg) administration. Blood samples were collected at appropriate times over 24 hours, and TCA concentrations in plasma were measured by high-performance liquid chromatography and radioimmunoassay. Free drug concentrations were determined by ultrafiltration for correlating pharmacokinetics and pharmacodynamics. The free fraction of TCA (+/- standard deviation) was 29.0 +/- 1.3% and was independent of the investigated concentration range up to 1,000 ng/mL. Pharmacodynamic parameters were determined by monitoring lymphocytes, granulocytes, and cortisol. Pharmacokinetic/pharmacodynamic modeling was performed using a modified Emax model for lymphocytes and granulocytes. A novel linear release rate model was used to characterize the cortisol data. The E50 values determined from all three pharmacodynamic endpoints were not significantly different for the three treatments, indicating that these effects can be explained based on systemic steroid concentrations.


Subject(s)
Anti-Inflammatory Agents/pharmacokinetics , Triamcinolone Acetonide/pharmacokinetics , Administration, Inhalation , Administration, Oral , Adult , Cross-Over Studies , Humans , Injections, Intravenous , Male , Protein Binding , Triamcinolone Acetonide/administration & dosage , Triamcinolone Acetonide/pharmacology
18.
Rofo ; 147(5): 493-7, 1987 Nov.
Article in German | MEDLINE | ID: mdl-2825282

ABSTRACT

After breathing pure oxygen, total atelectasis of one lung was produced in ten dogs; its development and regression was followed by CT and by conventional radiology. 30 seconds after cessation of ventilation, it was possible to show a rise in CT density of the atelectatic lung from -764 +/- 32 HU to -739 +/- 49 HU. The average time from the cessation of ventilation to total atelectasis averaged 5.5 +/- 1.1 minutes. The earliest sign on conventional radiographs was often seen after 30 seconds and usually after 60 seconds and consisted of mediastinal displacement. Extensive atelectasis regressed in only one out of six animals within one hour after resuming ventilation. The experimental methods and results and the significance of the physiological findings in a clinical context are discussed.


Subject(s)
Pulmonary Atelectasis/diagnostic imaging , Tomography, X-Ray Computed , Animals , Dogs
19.
Mar Pollut Bull ; 42(2): 91-120, 2001 Feb.
Article in English | MEDLINE | ID: mdl-11381890

ABSTRACT

Coral reef degradation resulting from nutrient enrichment of coastal waters is of increasing global concern. Although effects of nutrients on coral reef organisms have been demonstrated in the laboratory, there is little direct evidence of nutrient effects on coral reef biota in situ. The ENCORE experiment investigated responses of coral reef organisms and processes to controlled additions of dissolved inorganic nitrogen (N) and/or phosphorus (P) on an offshore reef (One Tree Island) at the southern end of the Great Barrier Reef, Australia. A multi-disciplinary team assessed a variety of factors focusing on nutrient dynamics and biotic responses. A controlled and replicated experiment was conducted over two years using twelve small patch reefs ponded at low tide by a coral rim. Treatments included three control reefs (no nutrient addition) and three + N reefs (NH4Cl added), three + P reefs (KH2PO4 added), and three + N + P reefs. Nutrients were added as pulses at each low tide (ca twice per day) by remotely operated units. There were two phases of nutrient additions. During the initial, low-loading phase of the experiment nutrient pulses (mean dose = 11.5 microM NH4+; 2.3 microM PO4(-3)) rapidly declined, reaching near-background levels (mean = 0.9 microM NH4+; 0.5 microM PO4(-3)) within 2-3 h. A variety of biotic processes, assessed over a year during this initial nutrient loading phase, were not significantly affected, with the exception of coral reproduction, which was affected in all nutrient treatments. In Acropora longicyathus and A. aspera, fewer successfully developed embryos were formed, and in A. longicyathus fertilization rates and lipid levels decreased. In the second, high-loading, phase of ENCORE an increased nutrient dosage (mean dose = 36.2 microM NH4+; 5.1 microM PO4(-3)) declining to means of 11.3 microM NH4+ and 2.4 microM PO4(-3) at the end of low tide) was used for a further year, and a variety of significant biotic responses occurred. Encrusting algae incorporated virtually none of the added nutrients. Organisms containing endosymbiotic zooxanthellae (corals and giant clams) assimilated dissolved nutrients rapidly and were responsive to added nutrients. Coral mortality, not detected during the initial low-loading phase, became evident with increased nutrient dosage, particularly in Pocillopora damicornis. Nitrogen additions stunted coral growth, and phosphorus additions had a variable effect. Coral calcification rate and linear extension increased in the presence of added phosphorus but skeletal density was reduced, making corals more susceptible to breakage. Settlement of all coral larvae was reduced in nitrogen treatments, yet settlement of larvae from brooded species was enhanced in phosphorus treatments. Recruitment of stomatopods, benthic crustaceans living in coral rubble, was reduced in nitrogen and nitrogen plus phosphorus treatments. Grazing rates and reproductive effort of various fish species were not affected by the nutrient treatments. Microbial nitrogen transformations in sediments were responsive to nutrient loading with nitrogen fixation significantly increased in phosphorus treatments and denitrification increased in all treatments to which nitrogen had been added. Rates of bioerosion and grazing showed no significant effects of added nutrients. ENCORE has shown that reef organisms and processes investigated in situ were impacted by elevated nutrients. Impacts were dependent on dose level, whether nitrogen and/or phosphorus were elevated and were often species-specific. The impacts were generally sub-lethal and subtle and the treated reefs at the end of the experiment were visually similar to control reefs. Rapid nutrient uptake indicates that nutrient concentrations alone are not adequate to assess nutrient condition of reefs. Sensitive and quantifiable biological indicators need to be developed for coral reef ecosystems. The potential bioindicators identified in ENCORE should be tested in future research on coral reef/nutrient interactions. Synergistic and cumulative effects of elevated nutrients and other environmental parameters, comparative studies of intact vs. disturbed reefs, offshore vs. inshore reefs, or the ability of a nutrient-stressed reef to respond to natural disturbances require elucidation. An expanded understanding of coral reef responses to anthropogenic impacts is necessary, particularly regarding the subtle, sub-lethal effects detected in the ENCORE studies.


Subject(s)
Cnidaria/drug effects , Marine Biology , Nitrogen/pharmacology , Phosphorus/pharmacology , Water Pollutants, Chemical/pharmacology , Animals , Bivalvia/drug effects , Bivalvia/metabolism , Cnidaria/metabolism , Crustacea/drug effects , Crustacea/metabolism , Eukaryota/drug effects , Eukaryota/metabolism , Fishes , Nitrogen/pharmacokinetics , Phosphorus/pharmacokinetics , Phytoplankton/drug effects , Phytoplankton/metabolism , Queensland , Water Pollutants, Chemical/pharmacokinetics
20.
J Hand Surg Br ; 19(1): 5-13, 1994 Feb.
Article in English | MEDLINE | ID: mdl-8169480

ABSTRACT

A study of endoscopic carpal tunnel release was carried out in three parts, consisting of initial cadaveric dissections, a prospective pilot study of 20 patients and a prospective, randomized trial of 71 patients comparing endoscopic with open decompression. In the main trial, 25 patients with bilateral symptoms underwent simultaneous endoscopic and open release, with the remainder randomized to one or other technique. Both techniques effectively decompressed the median nerve. A significant improvement in group and pinch strength over 3 months was achieved in those undergoing endoscopic surgery. Average return to work was 14 days in the endoscopic series and 39 days in the open series. A complication rate of 35% was achieved with the transbursal endoscopic technique, 3.7% with the extrabursal endoscopic technique and 13.5% in the open series.


Subject(s)
Carpal Tunnel Syndrome/surgery , Endoscopy , Adult , Aged , Female , Humans , Male , Methods , Middle Aged , Pilot Projects , Postoperative Complications , Prospective Studies
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